IN STARRY SKIES

Evening Post, Volume CXI, Issue 119, 22 May 1931, Page 16

IN STARRY SKIES

PRESENT ACTIVITIES AT GREENWICH

(By "Omega Centauri.") ■In ISSJ. W. H. M. Christie, another high Wrangler, succeeded 'Airy as Astronomer Royal. During his -!> years of office great developments look place. The number of departments, the buildings, and tho instrumental equipment were all increased. The new departments were' those of the Astrographic Chart and of Double Star Observation. Tho instruments installed wero a new altazimuth with an aperture of eight inches; the Astrographic twin telescope, the ~'b"-inch and 9-inch Thompson photographic refractors, the 30-inch reflector, and the 2Sineh refractor, tho largest of its kind in the British Empire. Such an increase in equipment necessitated a large amount of building. The chief addition was tho great new observatory in the' South ground. It contains the rooms of the Astronomer Koyal and his chief assistants, the computing ■rooms, rooms for tho storage of photographs, libraries, and workshops. This handsome three-story building is crowned by a great dome, beneath which 13 housed the Thompson photographic refractor. Other additions during Christie's reign were the new altazimuth building, the new libraries, the porter's lodge, and the magnetic, pavilion. By the end of the nineteenth century the staff had grown 10 03 members all told, very different from the single 'assistant- of the oarly' Hoynl Astronomers. When Christie retired in 1910,"ho was succeeded by F. W. Dyson, now Sir Frank Dyson. He was second Wrangler ;md Smith's Prizeman, and is the fifth Cambridge Astronomer Royal. He was chief assistant at Greenwich from 1801 to 1905, when he became-Astronomer Royal of Scotland. He was knighted in 1915, and in 1921 was awarded the Royal Medal for researches on the structure of the stellar universe. PRESENT ACTIVITIES. The original purpose of ihc Royal Observatory, to assist .navigation, has always been kept steadily in view. But with the advance of science methods have changed, and the mariner is not so directly in. touch with the stars ns ho used to be. The observatory, whilst still attending faithfully to all his needs, has gradually but inevitably extended its sphere of activity. It is i\n longer possible to draw a hard and fast ■ lino.between pure science and its practical applications. It would thus bo hard to show tho connection with practical navigation of some of the researches that are now carried on at Greenwich. Even the determination of the places.of tho stars and the motions of tho heavenly bodies is carried fat beyond the needs of the practical navigator. With the great Transit Circle over 10,000 transits are observed per year. During tho last seven years the actual number", wa5'72,219. These, observations have enabled standard catalogues to be prepared, and a new zone catalogue 'of stars between the . Equator and;.;deciination 24- degrees North was started on Ist January/ 1931. Accurate time is determined regularly, and the positions of tho sun, the moon, and clock stars arc predicted for years in advance. The altazimuth was not in use last year, but up to 1929 it was used for observations of tho crescent moon and of comparison stars to bo used in the observations of Eros. The Cookson floating zenith telescope is being'used for the determination of the minute variation n'hvjh takes place in latitude. During tho last two years 512 plates have been taken for this purpose ' ." '. '. The 28-inch refractor is now used for the observation of close double stars and., faint variables. During the iast two years nearly a thousand measurements have been made. The majority of tho double stars observed have a separation less.than two seconds of arc. The 26-inch Thompson equatorial is employed for the determination of stellar parallaxes. The visual 12i[-ineh refractor is used as a guidiug telescope. During tho last two years 2749 plates have been taken with this instrument. The plates are afterwards measured, and the parallaxes, when determined, are published in the Monthly Notices of tho B.A.S. ■ On ' the other end of the same declination axis is the 30-inch reflector which is used now chiefly in determining the colour temperatures of stars. A list of type stars has been prepared to servo as colour, standards. The telescope is also used, when occasion demands, for tho photography of comets and faint satellites. The eighth satellite of Jupiter was discovemVwith it by Melotte in 1908. The nstrographic equatorial has been used since. 1923 for tho determination of the propor inotious of stars. • On an average about. 50 plates are taken each year .through the. glass, so that the negatives/can bo,measured when placed film to .film with corresponding ones taken about thirty years before. With the photoheliograph a photograph of the sun is taken every day that it is possible. Most of tho gaps that occur at Greenwich are filled either by the Cape or Kodaikanal. Last year three days were missed, although the Capo had the excellent record of 34G good days. From the photos the area of the spots is found. The average spotted area, in niillionths of the sun's hemisphere, during the last seven years since the. minimum has been 27(3, 830, 1262,- 1058, 1390, 1242, and 500. With the spectrohelioscopo lent byMount Wilson Observatory, observations were obtained last year on 130 days. ■ I Special observations of Eros were • commenced early last October, and continued whenever the weather wa.s ' favourable. In addition to all these activities ' there-are the more practical clock and ' time service, the testing of ! chronometers, the local distribution of ' exact, time, and the transmission and reception of wireless time signals to i and from many parts of the world. ' Greenwich; Observatory is tho oldest ' and in many respects tho most import- ( ant of all existing ones. It i 3 a great ' tribute to the enterprise of British ' seamen and astronomers I hat the 1 meridian which passes through its , transit'instrument, has become the standard initial longitude for the whole ( world. Great as Greenwich is there are ( innumerable forms of astronomical re- .] search that it cannot, attempt. Will New'Zealand-rise'to the occasion and ' take its part in a great wave- of pro- ! gress by founding an observatory of the first class? Tho splendid work that i« ] being'dona in many parts-of tho world should be an incentive to all who are > able to do so to join in founding and ' endowing a great People's Observatory. Sites in New Zealand have been sug- ' gested where the climate is good and the seeing excellent. Tho problems aro ' many, the telescopes too few, and. in . our part of the world we have not yet . a single great one. '

! An ancient sepulchre in an excellent 1 state of preservation has been found in , a field near Letterkenny, County Done- , gal, Ireland. Inside the sepulchre was an '. urn containing ashes, lying among charred , bones. ' On 31st December, IUU, the tot.il dr.- ' posits in British post olKec savinas banks < were £170.518,508. On ."Ist Decembor, f 1929, the amount had risen to ,C 255,000- I 000. '